Excessive alcohol use is associated with considerable morbidity and mortality, leading to extensive research identifying factors associated with increased risks for the development of excessive alcohol use and for experiencing alcohol-related harm. Identified risk factors have spanned a number of distinct domains including contextual effects (e.g., alcohol outlet density, neighborhood social disadvantage) familial and individual specific environmental influences (e.g., parental separation, childhood abuse) and individual factors (e.g., genetic vulnerability, history of psychopathology). Typically, however, there has been limited integration across domains. Some have suggested that area-level factors, such as neighborhood conditions, may be more relevant to the theory of gene-environment (GE) interplay than other social factors. First, some individuals may be more frequently exposed to certain social contexts (e.g. neighborhoods with higher alcohol outlet density) as a consequence of their drinking (e.g. self-selection). Second, neighborhood conditions may enhance or constrain the relative influence of genetic influences on alcohol-related behaviors, by serving as an immediate form of social control that limits the manifestation of latent characteristics. We propose to add innovative measures of neighborhood environment (e.g. alcohol outlet density), generated using Geographic Information System (GIS) technologies, to previously collected data on a female adolescent twin cohort (N=1700 twin pairs), followed across multiple waves of assessment into young adulthood. This will allow us to better characterize the separate contributions of neighborhood, family and individual factors to early initiation of alcohol use (a major risk factor for subsequent excessive alcohol use), onset o drinking to intoxication, as well as heaviness of alcohol consumption and alcohol-related problems. It will also allow us to test both for self- selection effects (i.e. whether genetic and environmental factors influencing neighborhood choice and alcohol- related behaviors are correlated), identifying individual and family factors that may influence choice of residence in young adulthood and for moderation of genetic influences by neighborhood environment (i.e. gene-environment interaction). Thus, our proposed research will inform both ecological and epidemiological research traditions on alcohol use disorders. Such research may shed new light on the nature, scope, and effectiveness of local alcohol control policies depending on the mechanism by which neighborhood conditions and genetic liabilities covary or interact or to affect alcohol use.